Electrical jack



Dec. 5, 1967 J. R. BAILEY ETAL 3,

ELECTRICAL JACK Filed Dec. 29, 1964 INVENTORS ATT'YS United States Patent 3,356,800 ELECTRICAL JACK James R. Bailey, Chicago, and Kurt Lutzenberger, Arlington Heights, Ill, assiguors to Switchcraft, Inc., Chicago, 111., a corporation of Illinois Filed Dec. 29, 1964, Ser. No. 421,916 3 Claims. (Cl. 260-51139) ABSTRACT 0F THE DISCL'QSURE An electrical jack embodying a plate of insulating material forming a support base having an embossment formed on one side thereof, a plug stem receiving channel formed through the plate and embossment, plug stem engaging electrode means mounted on the embossment remote side of the plate, in position to electrically connect with a plug stem in the channel, and a grounding ferrule ensheathing the sides of the embossment, in position to make electrical contact with the grounding skirt of a plug, when its stem is mounted in the channel, in engagement with the electrode means.

The present invention relates in general to electrical circuit connection jacks, and has more particular reference to jacks having novel features facilitating the fabrication of jacks having optimum performance characteristics and allowing improved efiiciency in the manufacture and assembly thereof at low cost.

An important object of the present invention is to provide a device of the character mentioned comprising a support frame and an electrical circuit forming contact element or elements mounted thereon in position for circuit controlling engagement with a cooperating plug element when inserted in the jack, wherein the contact elementor elements may be quickly and easily assembled and secured on the support frame, in precisely located and oriented position, thereby simplifying and facilitating the rapid assembly of the improved jack.

Another important object is to provide a jack having a support frame of insulating material formed with a plug guiding channel, and a plug engaging contact or electrode mounted on the frame and having a pair of spaced arms disposed in alined position with respect to the channel for engagement with the opposite sides of a cooperating plug element when disposed in said channel.

A further important object is to provide the frame with a projection extending between the arms of the electrode, outwardly of the channel, to support the same in a desired spaced relation on opposite sides of the axis of said channel, in the absence of the plug; another important object being to form the electrode arm positioning finger of insulating material, whereby the arms of the plug engaging electrode are electrically connected only with the plug when the same is disposed in electrode engaging position in the channel; a still further object being to constitute the projection as a finger of electrical conducting mate rial forming a part of a circuit electrode secured on the frame, whereby said electrodes may form a normally closed switch in the absence of a plug in said channel, said switch being openable in response to the presence of a plug in the channel and between the spaced arms of said plug engaging contact.

Another important object is to form a circuit electrode comprising a sheet metal strip having a medial portion formed with an opening and mounting portions extending oppositely from and in a common plane with said medial portion and terminal portions bent from and extending angularly with respect to said mounting portions, in position the one to form a spacing finger between the arms of the cooperating plug engaging electrode and the other to form a circuit connection tab; a further object being to 3,356,800 Patented Dec. 5, 1967 attach the circuit forming electrode on the frame, as by means of a suitable fastener extending through said opening in the medial portion and clampingly engaging said frame and electrode, and to form one or more electrode locating projections in position engaging one of said mounting portions adjacent said opening.

Another important object is to provide an improved prong engaging electrode comprising a pair of plug engaging arms bent into parallel spaced relationship from a flat sheet metal blank, the medial portions of the blank, between said arms, forming an electrode mounting base having a central perforation and providing oppositely extending fingers or tabs, including a locating tab extending between and in the direction of said arms, on one side of said perforation, and an oppositely extending, upwardly bent finger formed to provide a preferably perforated circuit connection tab; a further object being to secure the plug engaging electrode on the support frame, as by means of a suitable fastener extending through said perforation and clampingly engaging said frame and electrode, and to form one or more electrode locating projections on the frame in position engaging said electrode locating tab.

Another important object is to form the spaced plug engaging arms with terminal blade portions, base connected mounting portions, and mutually outwardly inclined connection portions disposed between the blade portions and the mounting portions, whereby to resiliently support the blade portions in spaced relation for engagement with the opposite sides of a plug; a further object being to curve the opposite edges of the blade portions of the electrode outwardly on opposite sides of the central portions of the blade, whereby the medial portions of the blades may engage and make electrical contact with the p ug.

The foregoing and numerous other important objects, advantages, and inherent functions of the invention will become apparent as the same is more fully understood from the following description, which, taken in connection with the accompanying drawings, discloses preferred embodiments of the invention.

Referring to the drawings:

FIG. 1 is a perspective view of a jack structure embodying the present invention, the same being shown wit: a plug of conventional character mounted in the l FIG. 2 is an enlarged sectional view through the jack structure along the line 2-2 in FIG. 1;

FIG. 3 is a top plan view of the jack structure shown in FIG. 2;

FIG. 4 is a perspective view of a grounding ferrule which forms a component of the structure shown in FIG. 2;

FIG. 5 is a sectional view similar to FIG. 2 and showing a modified construction;

FIG. 6 is a top plan view of the jack structure shown in FIG. 5;

FIG. 7 is a plan view of a blank from which may be formed a plug engaging electrode embodying the present invention;

FIG. 8. is a top plan view of an electrode as formed from the blank shown in FIG. 7;

FIG. 9 is a perspective view of the electrode shown in FIG. 8;

FIG. 10 is a plan view of a blank from which may be made a circuit forming electrode embodying the present invention;

FIG. 11 is a perspective view of a circuit forming electrode made from the blank shown in FIG. 10;

FIG. 12 is a partially sectionalized side view of a plug of the sort adapted to be used with the jack of the present invention as shown in FIG. 1;

FIG. 13 is an enlarged partially sectionalized side view of portions of the plug shown in FIG. 12; and

FIGS. 14 and 15 are sectional views taken substantially along the lines 14--14 and 1515 in FIG, 13.

To illustrate the invention the drawings show a jack 11 adapted for use in conjunction with a plug 13 for making electrical connection between the stem or sleeve 15 of the plug and the plug engaging electrode 17 of the jack when the plug is in mounted position therein. As shown more particularly in FIGS. 1-6 of the drawings, the jack may comprise a generally rectangular, preferably squarish plate 19, having circularly rounded corners and openings 21, 23 formed through the plate, at its comers, and a centrally disposed, preferably cylindrical embossment 25 extending outwardly of the plate on one side thereof, said plate and embossment being formed with a channel 27 therethrough. The openings 21 may be formed at a pair of diagonally opposite corners of the plate and sized to receive studs or other fastening devices for attaching the plate to a panel or other mounting upon which it may be desired to secure the jack, the openings 23 being formed at the remaining diagonally opposite corners of the plate.

The plate 19 may also be formed with shallow circular bosses 29, at and around said corner openings, on the side of the plate on which the central embossment 25 projects. The plate may be formed with shallow elongated notches 31 in two of its opposite sides, medially between the rounded corners, a much deeper notch 33 being formed medially in a third side of the plate. The central embossment 25 may be circumferentially sheathed with a preferably cylindrical grounding ferrule 35 of electrical conducting material, the outer end ofthe ferrule having an inturned flange 37 overlying the outer end of the embossment 25, outwardly of the end of the channel 27. At its inner end, remote from the flange 37, the ferrule has oppositely extending anchoring fingers 39 disposed between the shallow bosses 29 on opposite sides of the plate, the terminal ends 41 of said fingers crimpingly embracing the edges of said plate, at the notches 31, which form seats for the accommodation of said crimped ends, to thereby secure the ferrule in position ensheathing the embossment. The ferrule may also have a preferably integral finger 43 extending thence in a direction normal to said anchoring fingers and offset to extend in the deep notch portion 33 of the plate, the extremity of said connection finger projecting through the notch to the side of said plate remote from said ferrule sheathed embossment.

Jacks embodying the present invention are adapted for use with plugs 13 of conventional character, an example of which is shown in FIGS. 1, 12 and 13. Such a plug may comprise a frame F, preferably of electrical conducting material having sleeve-like configuration providing a mounting cavity in one end for receiving insul-a tion I in which the stem 15 may be mounted and supported in position extending axially of the frame forming sleeve. The stem may comprise a hollow electrical conducting sleeve, as of metal, which projects coaxially through and outwardly of a preferably cylindrical skirt portion S of the frame, the projecting end of the stem being preferably rounded as shown to facilitate entry thereof between the blades of the plug engaging electrode 17 when the plug is applied in the jack. The opposite end of the sleeve 15 may project outwardly of the skirt remote end of the frame F for the sliding reception of the bared end E of the conductor of a cable C which may conventionally be enclosed in a woven electrical conducting sheath H. The bared end B of the conductor may be electrically connected with and within the stem 15, as by means of solder D.

Inwardly of the skirt portion S, the frame F may be provided with screw threads T. A grounding clip G is provided to electrically connect the cable sheath H with the frame F, said clip having a portion P adapted to be wrapped around and electrically connected with the cable sheath H and a portion R adapted to be clampingly received and held upon the insulating material I in the frame forming sleeve by the turned-over end edge K of said sleeve. The plug may also comprise a cylindrical cover V formed for detachable connection with the threaded portion T of the frame to secure the cover on the frame in position enclosing the grounding clip G and the end of the frame on which it is mounted, said cover being adapted to serve as a hand hold for the manipulation of the plug in applying it into and withdrawing the same from the jack.

The skirt S is sized circumferentially to snugly enclose and form a friction fit with and around the projection enclosing ferrule 35 of the jack, the skirt being preferably formed with a plurality of longitudinal slits Q from the outer edge thereof inwardly toward its connection with the frame F, The skirt portions between the slots, accordingly, may yield outwardly to permit the skirt to be readily applied upon and around the ferrule 35 and to anchor the plug frictionally thereon in mounted position in the jack. The skirt may also serve to coaxially aline the stem 15 of the plug within the guide channel 27 of the jack.

It will be seen from the foregoing that the sheath H of the cable C will be electrically connected with the frame F and thence to the skirt S, through the grounding clip G, and that said sheath H of the cable will be electrically connected through the ferrule 35 to its grounding lug 43 and thence to any ground circuit with which said lug may be electrically connected.

As shown more particularly in FIGS. 7, 8 and 9, the plug engaging electrode 17 may be formed from a sheet metal blank 45 having a medial portion 47 provided with a preferably circular perforation 49, the blank having oppositely extending finger portions 51 and 53 projecting from the opposite ends of the medial portion 47. The blank may also comprise lateral wing portions W extending at and outwardly of the opposite side edges of the medial portion 47, said wing portions including each a mounting portion '55 attached to the medial portion 47 of the blank, an intermediate portion 57 connected with the mounting portion and extending thence in parallel spaced relation with respect to the finger portion 53, and a tip portion 59 forming an extension of the intermediate portion, said tip portion projecting outwardly of the intermediate portion beyond the end of the finger portion 53.

The plug engaging electrode 17 may be formed from the blank 45 by bending the finger portion 51 and the lateral wing portions upwardly from and preferably at right angles with respect to the medial portion 47, as along the bend lines 61 and 63, whereby the wing portions are disposed in generally parallel spaced apart relation extending substantially at right angles with respect to the medial portion 47 and also with respect to the finger portion 51. The intermediate portions 47, preferably while the blank 45 is in flat unbent condition, are bent upwardly from the mounting portions 55, as along the bend lines 65, preferably at an angle of the order of 20, and the tip portions 59 are bent downwardly from the intermediate portions 57, as along the bend lines 67, preferably at a slightly lesser angle than that provided between the mounting and intermediate portions 55 and 57, the opposite sides of the tip portions 59 preferably being cnrvingly bent downwardly on opposite sides of a medial longitudinally extending bend line 69, whereby, in the plug engaging electrode, the mutually facing sides of the tip portions 59 are of generally convex curvature.

It will be seen from the foregoing that the tip portions 59 of the wing portions W provide a pair of spaced resiliently mounted plug stem engaging contact blades 59'. It will also be seen that the medial portion 47 of the blank may provide an electrode mounting base 47'. Ac-

cordingly, the electrode 17 may be mounted on the base plate or frame 19, at a corner opening 23 thereof, by stacking it with its base 47' resting on the side of the frame 19 opposite from the ferrule sheathed embossment 25, with the opening 49 in the electrode base in concentric alinement with the frame opening 23. The electrode may be secured in place on the frame by any suitable or preferred fastening means, such as a tubular rivet 71 sized to snugly fit through the openings 23 and 49. One end of the tubular rivet may be peened or rolled over upon the mounting base 47' of the electrode, around the opening 49, the opposite end of the rivet being similarly peened or rolled over upon a seat 73 formed on the electrode remote side of the frame around the opening 23. The electrode may thus be mounted on the rivet in position extending diagonally of the frame 19, with the contact blades 59' of the electrode disposed in line with the end of the channel 27 and on opposite sides of its axis, in position to receive therebetween and to make electrical contact with the stem 15 of a plug 13 when the same is in mounted position in the channel 27 of the jack.

In order to dispose and retain the electrode precisely in diagonally mounted position, the frame 19 may be provided with a pair of spaced apart preferably cylindrical projections or stubs 75 in position engaging the opposite sides of an alining tab 53 formed in the electrode by the finger 53 of the blank. The finger portion 51 of the blank may form a convenient electrical connection lug 51' on the electrode to facilitate electrical connection thereof in an external circuit.

The electrode 17 may be and preferably is formed so that the extremities of its contact blades 59' will be resiliently urged together and may mutually engage, as shown in solid lines in FIG. 8 of the drawings, in the absence of the plug stem 15 or other blade separating means therebetween. Accordingly, when the stem of the plug is inserted in the jack channel 27, with the tip of the stem disposed between the electrode blades 59, the latter may be separated to the position shown in dotted lines in FIG. 8, in which position the resilience of the electrode wing portions 57 along the lines of bend 63 and 65 will hold the blades 59' in position firmly pressing upon the opposite sides of the plug stem 15. If desired, support means 77 may be provided on the frame 19 in position extending between the tips of the electrode blades 59', outwardly of the channel 27, in order to support the blades in a desired spaced relation intermediate the blade positions shown in dotted and solid lines in FIG. 8, to thereby facilitate entry of the plug stem 15 between the blades, without, however, minimizing the engaging pressure of the blades upon the opposite sides of the stem 15, when the plug is in mounted position in the jack.

As shown more particularly in FIGS. 2 and 3 of the drawings, the blade support means 77 may comprise electrical conducting material adapted to form a blade engaging electrode 79 which may serve to electrically connect with the blades 59' of the electrode 17, in the absence of the plug stem 15 in electrode contacting position in the jack. When, however, the stem is in circuit forming position in the jack, thereby spreading the electrode blades 59, the same may be made to separate sufficiently to break connection thereof with the electrode 79. As a consequence, when the blade separating means 77 comprises an electrode 79, as shown in FIGS. 2 and 3, the electrodes 17 and 79 may be arranged to cooperate to form a normally closed electrical switch adapted to be opened in response to the insertion of the plug 13 in the jack.

As shown more particularly in FIGS. 10 and 11 of the drawings, the electrode 79 may be formed from a sheet metal strip having a medial portion 81 provided with a preferably circular opening 83 and a pair of oppositely extending finger portions 85 and 87 preferably integrally connected with the medial portion 8 1, said finger portions being bent preferably at right angles to the medial portion, as along bend lines 89 and 91 to form spaced apart, preferably parallel lugs and 87 on opposite sides of the medial portion 81, which may include a strip portion 93 between the opening or perforation 83 and the bend line 91.

It will be seen from the foregoing that the medial portion 81 of the blank will provide a mounting base 81 for the electrode 79, which may be mounted on the frame 19, at a corner opening 23' diagonally opposite the corner opening 23, by stacking the electrode on the side of the frame 19 opposite from the ferrule sheathed embossment 25, with the electrode opening 83 in concentric alinement with the frame opening 23'. The electrode may be secured in place on the frame by suitable fastening means, such as a tubular rivet 71', sized to snugly fit through the openings 23' and 83. One end of the tubular rivet may be peened or rolled over upon the mounting base 81 of the electrode, around the opening 83, the opposite end of the rivet being similarly peened or rolled over upon a seat 73' formed on the electrode remote side of the frame, around the opening 23. The electrode may thus be mounted on the rivet in position extending diagonally of the frame 19, with the upstanding finger 87 in position extending between the tips of the blades 59 of the electrode 17. The other upstanding finger 85' may provide 'a connection lug whereby the electrode 79 may be connected in an external electrical circuit.

In order to secure the electrode 79 on the rivet 71 precisely in diagonally oriented position, the frame 19 may be provided with a pair of projecting stubs 75, similar to the stubs 75 and disposed in position engaging the opposite side edges of an electrode alining portion 93 formed in the electrode by the extension 93 of the medial portion of the blank from which the electrode is formed.

If desired, as shown in FIGS. 5 and 6, the blade spacing means 77 may comprise a rod or bar of any suitable material formed on or mounted in the plate-like frame 19, in position extending between the tips of the blades 59. As shown, the blade spacing means may conveniently comprise a preferably cylindrical rod 95 of insulating material, such as the material of which the frame 19 is formed; and the rod 95, if desired, may be made as an integral part of the frame during the frame molding operation, or the rod may be formed as a separate element and then cemented or otherwise secured in an opening formed in the frame, as indicated by dotted lines at 95'. Frames thus may be produced on a mass basis having preformed openings 95 as well as the electrode alining projections or stubs 75', so that frames may be used at will either for assembly in jacks of the sort shown in FIGS. 2 and 3, or in jacks of the sort shown in FIGS. 5 and 6, or even in jacks omitting the spacing means 77 entirely.

It will be noted that the bosses 29, as shown in FIGS. 2 and 5, may be deep enough to project outwardly of the ferrule arms 39 which overlie the electrode remote side of the frame forming plate 19. Accordingly, the jack may be mounted upon a metal panel, as by means of studs or other fastening elements applied through the jack frame openings 21 and into the panel. The jack may thus be mounted on such a panel at a hole formed therein for the reception therethrou-gh of the ferrule sheathed projection 25, without grounding the ferrule or its arms on the panel, providing, of course, that the ferrule receiving hole is large enough to avoid engagement of the ferrule with its edges, the bosses 29 bearing upon the panel to prevent engagement thereof with the ferrule arms 39.

If, however, it is desired to provide a jack adapted for the direct electrical connection of its ferrule 35 with the panel on which it is mounted, the bosses 29 may be cut away or otherwise removed or omitted down to the level of the ferrule mounting arms 39, as indicated by the dotted lines 97 in FIGS. 2 and 5. When such a jack frame 19 is clamped upon a mounting panel, the ferrule arms 39 may form direct electrical contact with the panel, even though the hole formed to receive the ferrule sheathed projection 25 is large enough to prevent direct engagement of the ferrule 35 with the panel, at the edges of such opening.

It is thought that the invention and its numerous attendant advantages will be fully understood from the foregoing description, and it is obvious that numerous changes may be made in the form, construction and arrangement of the several parts withoutdeparting from the spirit or scope of the invention, or sacrificing any of its attendant advantages, the forms herein disclosed being preferred embodiments for the purpose of illustrating the invention.

The invention is hereby claimed as follows:

1. An electrical jack comprising a plate forming an insulating base having an embossment projecting from the plate on one side thereof, said embossment and plate hav ing a channel therethrough for the removable reception of the stem of a plug, a stern engaging electrode of sheet metal having a medial mounting portion, secured on the side of the plate opposite from said embossment, and wing portions at the opposite sides of and extending normal to the mounting portion to form a pair of spaced mutually facing electrode blades resiliently supported on said mounting portion, opposite said channel, and yieldingly separable to engagingly receive the stem of a plug applied through said channel, a ferrule of electrical conducting material sheathing said embossment, on one side of the plate, in position to slidingly engage and electrically contact with the grounding skirt of a plug when inserted in the jack, and a connection lug extending from the ferrule to the opposite side of the plate for connection in an external ground circuit.

2. An electrical jack as set forth in claim 1, wherein the ferrule, at the plate connected base of the embossment, is provided with radial arms extending to and crimpingly embracing the edges of the plate to hold the ferrule on the embossment, said arms serving to electrically connect the ferrule with any panel of conducting material upon which the arm carrying face of the plate may be applied in mounting the base on the panel.

3. An electrical. jack as set forth in claim 1, wherein the ferrule, at the plate connected base of the embossment, is provided with radial arms extending to and crimpingly embracing the edges of the plate to hold the ferrule on the embossment, said plate being formed with bosses, outwardly of and circumferentially spaced about said embossment, said bosses projecting outwardly of said radial arms in position to engage and to prevent electrical connection of said arms with any panel of conducting material upon which the arm carrying face of the plate may be applied in mounting the base on the panel.

References Cited UNITED STATES PATENTS 2,171,272 8/1939 Kronmiller et al 200-166 3,108,843 10/1963 Frantz ZOO-51.1 X 3,171,906 3/1966 Allison ZOO-166.1

FOREIGN PATENTS 145,610 6/ 1935 Austria. 294,765 8/1928 Great Britain. 621,459 4/1949 Great Britain.

ROBERT S. MACON, Primary Examiner.

ROBERT K. SCHAEFER, Examiner.

D. SMITH, Assistant Examiner. 

1. AN ELECTRICAL JACK COMPRISING A PLATE FORMING AN INSULATING BASE HAVING AN EMBOSSMENT PROJECTING FROM THE PLATE ON ONE SIDE THEREOF, SAID EMBOSSMENT AND PLATE HAVING A CHANNEL THERETHROUGH FOR THE REMOVABLE RECEPTION OF THE STEM OF A PLUG, A STEM ENGAGING ELECTRODE OF SHEET METAL HAVING A MEDIAL MOUNTING PORTION, SECURED ON THE SIDE OF THE PLATE OPPOSITE FROM SAID EMBOSSMENT, AND WING PORTIONS AT THE OPPOSITE SIDES OF AND EXTENDING NORMAL TO THE MOUNTING PORTION TO FORM A PAIR OF SPACED MUTUALLY FACING ELECTRODE BLADES RESILIENTLY SUPPORTED ON SAID MOUNTING PORTION, OPPOSITE SAID CHANNEL, AND YIELDINGLY SEPARABLE TO ENGAGINGLY RECEIVE THE STEM OF APLUG APPLIED THROUGH SAID CHANNEL, A FERRULE OF ELECTRICAL CONDUCTING MATERIAL SHEATHING SAID EMBOSSMENT, ON ONE SIDE OF THE PLATE, IN POSITION TO SLIDINGLY ENGAGE AND ELECTRICALLY CONTACT WITH THE GROUNDING SKIRT OF A PLUG WHEN INSERTED IN THE JACK, AND A CONNECTION LUG EXTENDING FROM THE FERRULE TO THE OPPOSITE SIDE OF THE PLATE FOR CONNECTION IN AN EXTERNAL GROUND CIRCUIT. 